Description

The refresh() and wrefresh() routines (or wnoutrefresh() and doupdate()) must be called
to get any output on the terminal, as other routines merely manipulate
data structures. The routine wrefresh() copies the named window to the physical terminal
screen, taking into account what is already there in order to do
optimizations. The refresh() routine is the same, using stdscr as the default
window. Unless leaveok() has been enabled, the physical cursor of the terminal is
left at the location of the cursor for that window.

The wnoutrefresh() and doupdate() routines allow multiple updates with more efficiency than
wrefresh() alone. In addition to all the window structures, curses keeps two
data structures representing the terminal screen: a physical screen, describing what is actually
on the screen, and a virtual screen, describing what the programmer wants
to have on the screen.

The routine wrefresh() works by first calling wnoutrefresh(), which copies the named
window to the virtual screen, and then calling doupdate(), which compares the
virtual screen to the physical screen and does the actual update. If
the programmer wishes to output several windows at once, a series of calls
to wrefresh() results in alternating calls to wnoutrefresh() and doupdate(), causing several
bursts of output to the screen. By first calling wnoutrefresh() for each window,
it is then possible to call doupdate() once, resulting in only one
burst of output, with fewer total characters transmitted and less CPU time
used. If the win argument to wrefresh() is the global variable curscr, the
screen is immediately cleared and repainted from scratch.

The redrawwin() routine indicates to curses that some screen lines are corrupted
and should be thrown away before anything is written over them. These
routines could be used for programs such as editors, which want a
command to redraw some part of the screen or the entire screen. The
routine redrawln() is preferred over redrawwin() where a noisy communication line exists
and redrawing the entire window could be subject to even more communication
noise. Just redrawing several lines offers the possibility that they would show
up unblemished.

Return Values

All routines return the integer ERR upon failure and an integer value
other than ERR upon successful completion.